Systems that generate terrain surfaces, such as ocean surfaces, using projected grid technique is known. In those systems, a grid in a screen space is projected from a projection point onto a plane in a world space. The projected grid creates a grid map on the plane such that the areas closer to the projection point are more densely occupied than those farther away from the projection point. Sampled vertices in such a grid map are processed to create features associated with specific terrains. For example, the sampled vertices may be displaced using associated height values to create a naturalistic appearance of a terrain surface. The so created terrain surface is then rendered in a field of view presented on a display.
On the display, the virtual terrain surface is typically presented in the field of view with a view point, the location of which is correlated with the location of the projection point in the world space (e.g., in some systems the projection point is the view point). Therefore, the projected grid will move as the view point moves. It is known that such movement of the project grid may cause artifact effects. For example, for a virtual ocean space presented on the display, the ocean surface may appear flicker or shudder as the view point moves sideways and causes the projected grid to slide over the ocean.